Wiring systems are provided in motor vehicles for the operation of electrical consuming units, also known as loads. Some types of consuming unit are particularly sensitive to voltage drop-outs or voltage spikes in the supply voltage, for example wiring system electronics or also the lighting. If this kind of sensitive consuming unit is exposed to a voltage drop-out or a voltage spike, its function can be at least partially impaired. This can impair the operation of the vehicle and/or unwanted side-effects can occur such as a brief dimming of the lighting of the motor vehicle.
Dynamic electrical consuming units are, furthermore, present, particularly in modern vehicles, the operation of which can cause a heavy voltage drop-out, for example a starter motor of a start/stop module or a drive of an electrical steering as is used by parking assistants. These dynamic consuming units in particular are activated during operation of the vehicle, and not only at a first cold start or when shutting the vehicle down.
A wiring system topology with a plurality of subsidiary networks is presented in DE 10 2012 203 467 A1, in which amongst other things sensitive loads, whose function depends on the operating voltage, are supplied, and loads are also supplied whose operating voltage of 12-14 V can be variable (within limits) without functional disadvantages for the load concerned. It is, however, recognized that there is a need for improvement in the supply of sensitive loads, in particular during start procedures.